Field of the Invention
The present invention relates to a method and an apparatus for welding a 3D bellows, and the bellows, and more particularly, to a method and an apparatus for welding a 3D bellows that is composed of a plurality of unit cells by connecting a plurality of unit cell materials laminated by two-time thermal welding work, in which the unit cells are connected by baffles and the insides of the unit cells are connected, and to the bellows.
Description of the Conventional Art
In general, an air mattress can be expanded by injecting air and folded and easily kept by discharging air, so it can be used not only for bed at home, but at various places such as a floor of a camping place, a medical bed, a narrow rest space in a ship, and an outdoor rest place, and a waterside excursion.
The most important issue when using an air mattress is whether it can support a body by distributing load throughout the entire area without a specific portion of the entire area, where load is applied, giving in, and whether air can be smoothly injected and discharged.
In a common air mattress structure of the related art, the entire inside is formed by a single space (unit cell) and a plurality of baffles is attached with regular intervals in the single space.
The baffles are composed of main baffles bonded by an adhesive to the upper side and the lower side in the single space of the air mattress, upper sub-baffles bonded to a side of the upper ends of the main baffles and the upper side of the single space, and lower sub-bafflers bonded to a side of the lower ends of the main baffles and the lower side of the single space.
The baffles prevents air from keeping expanding up and down by holding the upper end and the lower end of the mattress when air is injected into the single space of the air mattress.
However, since the inside of the air mattress is formed by a single space, when external pressure (for example, body weight) is applied to a specific area of the air mattress, the air in the air mattress moves to the other portions except for the specific area where the external pressure is applied and the specific area of the air mattress gives in, so it cannot uniformly and elastically support the body of the user.
Further, a plurality of baffles are manually bonded to the upper and lower sides in the air mattress, many work processes are required and work time is too long, so workability is deteriorated, and accordingly, productivity for mass production reduces and the manufacturing cost increases.
In order to solve this problem, the applicant(s) has proposed “Air mattress and, equipment and method for manufacturing the same” (Korean Patent Application No. 10-2011-0143626).
According to this air mattress, an upper cover member fabric and an lower cover member fabric are supplied in one direction with a predetermined gap therebetween, baffle holes are formed with regular intervals through the upper cover member fabric and the lower cover member fabric, and baffle wicks having a predetermined length are inserted into the baffle holes in the upper and lower cover member fabric.
Further, the upper ends and lower ends of the baffle wicks protruding over the outer surfaces of the upper and lower cover member fabrics through the baffle holes in the upper and lower cover members are attached to the outer surfaces of the upper and lower cover members, the edges of the upper and lower cover members are sewn, and then a plurality of air tubes are put between the baffle wicks in the upper and lower cover members.
However, the air mattress of the related art is manufactured through many steps, as described above, a step of forming baffle holes in the upper cover member fabric and the lower cover member fabric, a step of inserting baffle wicks into the baffle holes, a step of bonding the upper and lower ends of the baffle wicks to the upper cover member fabric and the lower cover member fabric, a step of sewing the edges of the upper cover member and the lower cover member, and a step of putting air tubes between the baffle wicks, so the manufacturing process is still complicated and the manufacturing cost is increased accordingly.
Further, the thermal welding method of the related art is a method of transmitting heat up and down to an XY plane using high frequency waves, ultrasonic waves, and an induction heater, so there is a limit in simultaneously welding a plurality of laminated mother materials or welding a thick mother material.
That is, the thermal welding method of the related art is not a method of horizontally transmitting heat in a Z-direction, so there is a limit in melting a plurality of laminated mother materials at a time or welding a thick mother material.